We use aluminum on a day-to-day basis. To be honest, it is pretty hard to even imagine our daily lives without this element. So, this element is nothing short of a wonder. In this article on aluminum facts, we will learn about the element in details. When we say details, we mean the history of aluminum discovery, its properties, its physical appearance and more. So, without further ado, let us begin.

To start with, let us get some quick information about the metal…

Element Name

Aluminum or Aluminium

Element Symbol

Al

Element Family

Basic Metal

Color

Silvery

State

Solid

Atomic Weight

26.98154 g/mol

Melting Point

933.57 K or 660.32°C

Boiling Point

2740.00 K or 2466.85°C

Density at 20°C

2.702 g/cm3

Number of Electrons

13

Number of Protons

13

Number of Neutrons (as found in most abundant isotope)

14

Electronic Configuration

1s2 2s2 2p6 3s2 3p1

Known Isotopes

24 isotopes known so far and 4 isomers

Element Structure

Face-Centered Cubic

Atomic Radius

125 pm

Hardness

2.8 mohs

Known Isotopes of Aluminum

Isotope Name

Type and Abundance

Half Life (HL)

19Al

Radioactive

<35 ns

20Al

Radioactive

<35 ns

21Al

Radioactive

<35 ns

22Al

Radioactive

59ms

23Al

Radioactive

470ms

24Al

Radioactive

2.053s

25Al

Radioactive

7.183s

26Al

Radioactive but Naturally Occurring

Abundance: <0.1%

7.17×105 years

27Al

Stable and Naturally Occurring

Abundance: > 99.9%

Does not decay and hence, no HL

28Al

Radioactive

2.2414min

29Al

Radioactive

6.56min

30Al

Radioactive

3.60s

31Al

Radioactive

644ms

32Al

Radioactive

31.7ms

33Al

Radioactive

41.7ms

34Al

Radioactive

56.3ms

35Al

Radioactive

38.6ms

36Al

Radioactive

90ms

37Al

Radioactive

10.7ms

38Al

Radioactive

7.6ms

39Al

Radioactive

7.6ms

40Al

Radioactive

10ms *

41Al

Radioactive

2ms *

42Al

Radioactive

1ms

* means that the data has been derived partly from systematic trends and is not purely experimental data.

Isomers of Aluminum

Isomers

Type and Abundance

HL

23mAl

Radioactive

~0.35s

24mAl

Radioactive

131.3ms

26mAl

Radioactive

6.3452s

32mAl

Radioactive

200ns

Now that we have our tables in place, let us start with the facts:

Aluminum Facts: 1-5 | History and Discovery

1. Aluminum has always been in use since ancient times. The only thing – it was never used in pure elemental form during those days. The compound of aluminum that was in use was known as alum.

2. Alum is nothing but potassium aluminum sulfate which had a number of applications such as stopping bleeding, tanning, dyeing etc.

3. It was only in 1750s that a stunning discovery was made by Andreas Marggraf – a chemist from Germany. He noticed that when alum was dropped into an alkaline solution, a new substance precipitated.

4. That was as far as Marggraf could go but he was the one who had previously isolated zinc. Anyway, the new substance that Marggraf managed to precipitate was named as alumina by Louis de Morveau by a French chemist. Today we know that alumina is basically aluminum oxide with a chemical formula of Al2O3.

5. Unfortunately, just like Marggraf, Morveau was also unable to isolate aluminum but he strongly believed that what Marggraf had found had a metallic element hidden in it.

Aluminum Facts: 6-10 | History and Discovery

6. Then came Humphry Davy – a chemist from England who used an electric arc for decomposing alumina and managed to get a metal. This happened in 1807 or in 1808. Davy first named the metal as alumium and only later named it as aluminum.

7. Hold on! Davy wasn’t the person who isolated aluminum. He actually managed to get an alloy of iron and aluminum. Isolation of aluminum didn’t take place until 1825.

8. The feat of isolating aluminum was achieved in Copenhagen, Denmark by Hans Christian Ørsted. He used potassium-mercury amalgam for reducing aluminum chloride and what was left behind was aluminum mixed with mercury.

9. In order to remove mercury, Ørsted heated the end result and mercury was removed, leaving behind pure aluminum that he referred to as a lump of metal that closely resembled tin in both luster and color.

10. Unfortunately, Ørsted was not credited with discovery of aluminum. This is because of Friedrich Wöhler – a German chemist. Wöhler tried reproducing Ørsted’s experiment only to get potassium metal. So, he took two more years to refine the process of aluminum extraction.

Aluminum Facts: 11-15 | History and Discovery

11. What Wöhler did was that he used potassium and reacted it with volatalized aluminum trichloride. Aluminum was produced as an end result but in very small quantities.

12. Berzelius in 1856 said that since Wöhler could not replicate Ørsted’s experiment but managed to isolate aluminum on his own using a separate method, Wöhler is the one who discovered aluminum in 1827.

13. So, Wöhler was given the credit of discovering the element. However, more recently came Fogh. He managed to repeat Ørsted’s experiment and found satisfactory results. So, priority of Ørsted increased and his position as the aluminum discoverer improved.

14. After Ørsted and Wöhler, aluminum was produced but only in small quantities because potassium that was used for the production was really expensive.

15. In 1854 came Henri Saint-Claire Deville from Paris in France. He managed to make the production of aluminum inexpensive by using sodium instead of potassium. In 1886 came chemists Paul Héroult from France and Charles Martin Hall from America. They independently devised the same method of isolating aluminum from alum using electrolysis. This method is today known as Hall-Héroult process.

Aluminum Facts: 16-20 | Characteristics of Aluminum

16. As far as harmful effects of Aluminum are concerned, there is no documented knowledge on this. However, scientists have the opinion that ingesting aluminum can lead to Alzheimer’s Disease.

17. Pure aluminum is silvery-white in color. It is a paramagnetic element. This means that its magnetism is very very weak under normal conditions and hence, it will not stick with magents.

18. The element is extremely reactive and this means that it is really hard to find pure aluminum metal in nature. However, there are rare instances where pure aluminum has been found in nature.

19. The element is highly ductile and has low density. It is also a very good (actually excellent) conductor of electricity.

20. Though aluminum is silvery-white in color in its pure form, what we usually see is a dull appearance when it is left out in open air. This happens because the element reacts with air to form aluminum oxide, which forms a protective coating on the element to prevent corrosion.

Aluminum Facts: 21-25 | Characteristics of Aluminum

21. The thin film of aluminum oxide that forms on pure aluminum when left in open air can be easily thickened using oxidizing agents or electrolysis. Once the film is thickened, it makes aluminum resistant to concentrated nitric acid, dilute alkalis and dilute acids.

22. Aluminum is pretty unique. It displays properties of both metals and non-metals. It behaves like typical metals when it reacts with acids and produced hydrogen and Al3+ (a positively charged metal ion).

23. It also reacts with hot alkalis and behaves like non-metals forming aluminate ions [Al(OH)4]–. Because aluminum behaves both like metals and non-metals, it is known as amphoteric.

24. In case you didn’t know (or perhaps you have already observed from the first table above), aluminum is actually pretty soft and lacks strength. On Mohs scale, it has a hardness of 2.8

25. So, in order to make use of aluminum in commercial applications, the element is always mixed with small amounts of iron and silicon (less than 1%). This improves the strength and hardness of the metal significantly and hence, makes it usable in commercial applications.

Aluminum Facts: 26-30 | Abundance and Beyond Earth

26. Aluminum is really abundant. In Earth’s crust, this element makes up 8.23% by weight. In terms of moles, it makes up 6.32% of crust of Earth.

27. In entire solar system, abundance of aluminum is 56 ppm by weight and in terms of moles it has an abundance of 2.7 ppm.

28. Wondering just how much those figures mean? In Earth’s crust, it THE MOST ABUNDANT METAL. If we look at MOST ABUNDANT ELEMENT in Earth’s crust, aluminum takes the third spot just after oxygen and silicon.

29. We mentioned earlier that aluminum is too reactive to be obtained in pure form in Earth’s crust. It is actually found in form of various compounds of which aluminum oxide or alum is the most abundant ore.

30. Aluminum is also produced in heavy stars. It is formed during fusion reactions in which magnesium is known to pick up an additional proton to form aluminum. Magnesium in turn is first produced by fusion reaction is stars where two carbon atoms fuse together to form magnesium.

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Aluminum is not transparent however, there is something called transparent aluminum. It is Aluminum Oxynitride made using nitrogen, oxygen, and aluminum. It is a transparent polycrystalline ceramic with a cubic spinel crystal structure.